Habitat Occupancy and Detection of the Pacific Sheath-Tailed Bat (Emballonura semicaudata) on Aguiguan, Commonwealth of the Northern Mariana Islands

Abstract

Occupancy analysis was used to quantify Pacific sheath-tailed bat (Emballonura semicaudata) foraging activity and its relationship to forest structure and proximity to cave roosts on Aguiguan Island in the Commonwealth of the Northern Mariana Islands. Bat occurrence was most closely associated with canopy cover, vegetation stature and distance to known roosts. The metrics generated by this study can serve as a quantitative baseline for future assessments of the status of this endangered species following changes in habitat due to management activities (e.g., feral goat control) or other factors (e.g., typhoon impacts). Additionally, we provide quantitative descriptions of the echolocation calls of E. semicaudata. Search-phase calls were characterized by a relatively narrow bandwidth and short pulse duration typical of insectivores that forage within vegetative clutter. Two distinctly characteristic frequencies were recorded: 30.97 ± 1.08 kHz and 63.15 ± 2.20 kHz